16.5 Anatomy: Muscles of the upper limb Flashcards
What does the pectoral girdle allow?
Scapula to move on thoracic wall
What are the extensions/processes of the scapula?
Posterior: acromion
Anterior: Coracoid process
What are the muscles that attach the pectoral girdle to the trunk from the thoracic wall? (4)
Pectoralis Major
Pectoralis Minor
Subclavius
Serratus Anterior
What are the muscles that attach the pectoral girdle to the trunk from the vertebral column? (5)
Trapezius Latissimus Dorsi Levator Scapulae Rhomboid Major Rhomboid Minor
What stabilises the clavicle?
What stabilises the scapula?
Subclavius
Pectoralis minor
What does Pec major do? (3)
Adductor and medial rotator, also an accessory muscle of inspiration
What underlies pec major?
Subclavius, pec minor
What is serratus anterior also called? What does it do?
What happens if the nerve supply is damaged?
Boxer’s muscle
Keeps scapula against chest wall during protraction
Winged scapula can occur
What are the muscles attaching the humerus to the scapula?
Which ones are the rotator cuff muscles? (4)
Deltoid Subscapularis* Supraspinatus* Infraspinatus* Teres minor* Teres major
What inserts onto the superior, middle and inferior facet of the greater tubercle of the humerus?
Superior: Supraspinatus
Middle: Infraspinatus
Inferior: Teres minor
What converges onto the lesser tubercle of the humerus?
Subscapularis
What are the muscles of the anterior compartment of the arm? What do they do?
Coracobrahialis
Biceps
Brachialis
(flexors)
What are the muscles of the posterior compartment of the arm? What do they do?
Tricepts
Extensors
What does teres major do?
Adductor and medial rotator
Where do the short and long head of biceps originate from?
Short head: corocoid process
Long head: supraglenoid tubercle (scapula)
-Intracapsular, extrasynovial
Where does biceps insert?
Crosses elbow joint, inserts into radial tuberosity (tendinous attachment)
What are the superficial and deep muscles of the arm?
Superficial: biceps, triceps
Deep: coracobrachialis/brachialis, triceps (deep)
Where does the coracobrachialis insert? What pierces it?
Midshaft of humerus
Musculocutaneous nerve pierces it
What is the ‘rule’ for superficial and deep muscles?
Superficial: proximal origin, inserting distally
Deep: arise from shaft of long bone that they overlie
What does coracobrachialis do?
What does brachialis do?
Weak action on shoulder joint (flexion, adduction)
Flexes forearm/elbow
What does biceps do?
Flexes arm, but supinator when elbow is mid prone
What are the heads of the triceps? Where do they attach?
Superficial: long (scapula), lateral (humerus)
Deep: medial (shaft, humerus)
Where does triceps insert?
Olecranon process of the ulna
Where is the common flexor origin?
What group of muscles arise from there?
Medial epicondyle of the humerus
Superficial muscles of the forearm
What are the superficial muscles of the forearm? (5)
Which ones have 2 heads?
Pronator teres* Flexor carpi radialis Palmaris longus Flexor digitorum superficialis* Flexor carpi ulnaris*
Where do superficial muscles of the forearm insert?
Pronator teres inserts onto lateral aspect of radius
Other four reach wrist
Which muscle is often considered the intermediate muscle?
FDS (bulk of anterior compartment of forearm)
Where do FCR and FCU insert?
FCR: base of 2nd/3rd MC
FCU: Pisiform (ligament extends into base of 5th MC)
Where do each of the 2 heads in the superficial muscles of the forearm originate from?
PT: CFO and ulna head (median nerve between)
FDS: extensive proximal attachment to all bones (median nerve under fibrous arch)
FCU: CFO, proximal ulna
